Module 2:
WAVES AROUND
YOUArchie A. Duran
Waves are all
around us…
Throwing a stone into
a lake
Strumming the strings
of a guitar
Switching on of a lamp
Water waves
Sound waves
Light waves
Importance of
Waves
Helps explain phenomena in
nature
Helps in designing
skyscrapers and bridges
Helps in improving
telecommunication and
What is a WAVE???
a wave is a periodic
disturbance that moves away
from the source and carries
energy
regular
movement
Activity 1: Let’s
make waves
Objective
In this activity, you will observe
and draw different types of
waves and describe how they
are produced. You will also
describe the different types of
3 types of Waves
Transverse Waves
Longitudinal Waves
Surface Waves
transverse
perpendicular
longitudinal
circular
Anatomy of a Wave
Crest
Trough
Amplitude
Wavelength
Crest
The highest points of a
wave.
Trough
Lowest points of a wave.
Amplitude
The maximum displacement
of a wave from the
equilibrium.
Wavelength
Distance from two
successive crest or trough.
Frequency vs.
Period
Frequency
The number of waves that
pass a reference point for
one second.
Units: 1 cycle/second = 1
Hertz
Period
The time needed for one
complete wave to pass a
reference point.
Unit: seconds
Frequency-Period
Relationship
Frequency is the reciprocal
of period
Period is the reciprocal of
frequency𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 =
1
𝑝𝑒𝑟𝑖𝑜𝑑
𝑃𝑒𝑟𝑖𝑜𝑑 =
1
𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦
Sample Problems
A young girl is on a swing
that completes 20.0 cycles
in 25 seconds. What are its
frequency and period?
A clock clicks 88 times in 22
seconds. Calculate the
frequency and period of the
clock.
A spring vibrates 24, 000 times
in 1.00 minutes. What are the
frequency and period. [Hint:
frequency is cycles per second.]
Wave Speed
The distance travelled of a
wave per unit of time.
Distance = wavelength
Time = Period
or
𝑊𝑎𝑣𝑒 𝑆𝑝𝑒𝑒𝑑 =
𝑊𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ
𝑃𝑒𝑟𝑖𝑜𝑑
𝑊𝑎𝑣𝑒 𝑆𝑝𝑒𝑒𝑑 = 𝑊𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ 𝑥 𝐹𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦
Examples
A vibrating source with a
frequency of 20.0 Hz
produces water waves that
have a wavelength of 3.0 cm.
Calculate the speed of the
waves.
A wave along a guitar
string has a frequency of
540 Hz and a wavelength
of 2.5 meters. Calculate
the speed of the wave.
Relationship
between
wavelength,
wave speed,
frequency, and
energy.
As wavelength increases,
wave speed ____________.
As wavelength decreases,
wave speed ____________.
As wavelength increases,
frequency __________.
As wavelength decrease,
frequency __________.
As frequency increases,
wave speed ____________.
As frequency decreases,
wave speed ____________.
Mechanical Waves
vs.
Electromagnetic
Waves
Mechanical Waves
Are waves the can only be
transmitted with the presence
of a medium.
Medium can be solids, liquids,
or gas
Electromagnetic
Waves
Are waves that can be
transmitted even without the
presence of a medium.
Ex. Radiowaves, x-ray,
microwave, UV waves,
Mental
Exercise...
1. What happens to
energy as wavelength
increases?
2. As wave speed
decreases,
wavelength
_______________.
3. What happens to
frequency as wave
speed increases?
4. As wavelength
decreases, wave
speed
________________.
5. As energy
increases, what
happens to wave
speed?
6-7. Give the 2
formula used in
computing wave
speed.
8-10. Give the 3
classification of waves
based on the motion
of wave from its
source.
11. Frequency is
said to be the
reciprocal of
_____________.
12. The highest
points of a wave
are known as
________________.
13. The distance
from crest to the
next crest is known
as ________________.
14-15. Give the 2
classification of
wave based on the
requirement for
medium.
Next
Module:
SOUND

Third Grading Module 2 Waves Around You